Flowing from North to South through the heart of Nagoya city, the Horikawa
River is a man-made canal that was excavated during the construction of
Nagoya Castle around 400 years ago.Excavated by
order of the feudal lord Fukushima Masanari, its original purpose was to serve
as a waterway enabling ships to supply the city with large amounts of goods
such as rice, vegetables, fish, and salt.The Horikawa River’s ability to transport goods spurred the development
of various industries, and thus the river has for many years been so intimately
connected with the lives of the citizens that they have traditionally called it
“Nagoya’s Mother River”.However,
pollution caused a steady degradation in water quality from the beginning of
the Showa period in the 1920’s.By
the time this pollution peaked in the 1960’s, the Horikawa had degenerated into
a foul, stinking flow choked with sludge.

In recent years, the City of Nagoya has been working to revitalize the
Horikawa River by dredging up the sludge and making repairs to the embankments,
and as a result significant progress can be seen in both water clarity
as well as maintenance of the river environment and surroundings.However, due to a number of reasons, a radical improvement in water
purity has thus far been elusive.For example, the Horikawa River lacks its own water source (instead relying
on wastewater processed by sewage treatment plants), and so the water tends
to stagnate.Furthermore, at high tide a large volume of eutrophic seawater from Nagoya
Bay flows backwards into the river, and it cause bad influence on water
quality. So it is necessary to increase the proportion of pure water to
prevent these from happening.For reasons like these, it is the present situation that despite the best
efforts of the administration and the sincere wishes of the citizens, a
dramatic improvement to the Horikawa River environment has yet to be realized.

2. Civic Activities Supporting Clarification of the Horikawa River

In May 1999, a coalition of around 30 Lions Clubs in Nagoya carried out
a signature campaign to support the early realization of raw water transmission
from the Kiso River to the Horikawa River.They were able to collect nearly 200,000
signatures in under two months.The
appeals of these and other citizens’ groups were successful in initiating
countless civic activities, such as the planting of 10,000 tulips along the
Horikawa River, the Horikawa Photo Contest, a symposium, a convention of
elementary school students in support of the river, a clean-up campaign, and
many more, demonstrating the citizens’ broad support for clarification of the
Horikawa River while at the same time realizing concrete progress in cleanup
activities.In response to will of
the people, starting from July 2001 the administration has carried out
provisional transmission of water (0.3 m3/sec) from the Shonai River to the Horikawa River.

In order to gauge
the effects of this provisional transmission in areas such as water quality
improvements, creation of a river culture, and “green city” redevelopment,
citizens’ groups proposed the creation of a “Horikawa River 1000-Citizen Survey
Network”.In September 2003, this
proposal was officially adopted as an “All-Japan Urban Renewal Model
Enterprise”, upon which the Nagoya Horikawa Lions Club and other civic groups
set out to recruit 1000 citizens for this “Horikawa Sen-nin Chosatai”.During the two-month application period,
they exceeded all expectations, receiving applications from 217 individual
groups and 2007 citizens in total.With a broad cross-section of participants young and old, male and female, from elementary, junior high school, and university students to boy scouts, private companies, citizens, and administrators, this endeavor has grown to be a civic social participation experiment of the grandest scale.

4. Nagoya City's Horikawa River Clarification
Measures and Organization of the Second Horikawa Sen-nin Chosatai:

Based on issues proposed during the first Horikawa Sen-nin Chosatai, Nagoya City decided to carry out the following three measures (experiments) aimed at clarification of the Horikawa River.

1.)Advanced Treatment at the Meijo Sewage
Treatment Plant (Short-term Coagulant Addition Experiment)
This one-month experiment investigated the effects on water quality
(particularly water clarity) that result from adding a coagulant to the final
effluent of the Meijo Sewage Treatment Plant in order to remove suspended
solids.This plant supplies water to the Horikawa River at the rate of 0.6 m3/sec.

2.)Transmission of Operational Water from
Nabeya-Ueno Water Clarification Plant (0.04 m3/sec)
At the water clarification plant, sampling water produced for water quality
tests as well as drainage water for backwashing the rapid sand filters has
traditionally been reused as raw water, but it has been permanently diverted to
the Horikawa River, and the effect upon water quality was investigated.

3.)Transmission of Shallow Underground Water
(0.01 m3/sec)
Underground water drawn from shallow test wells around the upper Horikawa
River (in order to inspect the water table, etc.) was discharged into the
Horikawa River, and the effect on water quality was investigated.

Figure 2 shows an
outline of these three measures.

To confirm and evaluate these measures from the citizens’ point of view,
planning and recruitment for this second Survey Network (or, “The Horikawa
Sen-nin Chosatai 2005”) was jointly conducted by the City of Nagoya and
the Nagoya Horikawa Lions Club.

As the area affected by this “Horikawa Sen-nin Chosatai 2005” was expected
to fairly limited, recruitment was targeted at around 50 teams, but in
only one month of recruitment in September 2005, the target was surpassed
by more than 100%, with 108 teams and a total of 730 people applying.In October of that year, briefings were
conducted, groups were organized, and survey activities began.

6.) Results of the
Investigation and Accomplishments of the Horikawa Sen-nin Chosatai 2005Investigative
activities were conducted from October to December 2005, and because the
results of each report were made public through the Internet as soon as they
became available, it had already become obvious both to the Chosatai team
members and to observers that this experiment had a measurable effect on water
quality, with the improvements to sewage processing and transmission of clean
water to the Horikawa being clearly vital to cleanup plans for the river.Mayor Matsubara of Nagoya City made an official announcement of the survey
results, publicly acknowledging the observed effects on water quality.He gave a positive evaluation of the expanding networks to clarify the
Horikawa River, and announced progressing to introduce advanced sewage
treatment at the Meijo facility on a permanent basis by 2010, in time to
commemorate the 400th anniversary of the Horikawa River’s excavation.

In addition, on
February 13th, the City of Nagoya announced the start of a new 3-year experiment, Transmission
of Raw Water from the Kiso River to the Horikawa River (hereafter referred
to as “TRWKR”).This represented a major
step towards fulfilling the citizens’ long-awaited dream, embodied in those
200,000 signatures some 7 years prior.On March 29th, a throng of citizens had gathered in the Kita Ward Office to hear the official announcement of these results, resolving to assemble a third Chosatai when TRWKR was enacted, so that they might advance step by step towards the goal of a clean Horikawa River.

7.
TRWKR: The Three-Year Social Experiment and Organization of Horikawa Sen-nin
Chosatai 2010

(Expansion of Civic Movements, Realizing a Partnership between Public and
Private, and Spreading Information to the World)

After learning the results of the Second
Chosatai, the governments of Japan and Nagoya spent around a year coordinating
with the various groups involved, and on March 27th, 2007, finally
announced the start of the three-year TRWKR Social Experiment. Fig.3 shows an
outline of it. The Aqueduct for water purification plant and the storm-water drainage
are utilized as raw water transmission root. Along with this, formation of the
Third Horikawa Sen-nin Chosatai was planned, but now with a much broader
scope—to secure the participation of a wide range of participations, an
executive committee was formed not only from the Lions Club but from many other
civic groups as well.Recruitment was then initiated under the joint direction of this executive
committee and the City of Nagoya.

Furthermore, in order to further expand the civic network of Horikawa
River Lovers, a new “Horikawa Cheering Groups” program was initiated,
by which citizens could freely show their support for the Horikawa River
Clarification Program in whatever way they like, without being restricted
to the “Survey” aspect.During three weeks of recruitment, there
were 165 teams totaling 2,262 applicants.At the present time, there are over 3,000 citizens registered.

The Horikawa
Sen-nin Chosatai 2010 began with three programs: “Fixed Point Observation
Groups” for the most earnest and dedicated citizens, “Free Survey Groups” for
university students and similarly interested parties, and “Horikawa Cheering
Groups” in which a wide range of individuals and companies can participate as
they see fit.One of these
branches, the “Fixed Point Observation Groups”, launched the 1st
stage of their activities from April 22nd to June 30th,
2007.To endure the marathon 3-year
stretch of this Third Chosatai, it is being divided into two stages per year, 6
in total, in order to allow for breaks and to keep participants sharp.In addition, this enables step-up
improvements – problems encountered in one stage can be translated into process
improvements for the next.